ICRF Experiments and Potential Formation on the GAMMA 10 Tandem Mirror

Abstract

Target plasmas, on which the formation of the electrostatic potentials and the improvement of the confinement are studied, are produced with ICRF in the GAMMA 10 tandem mirror. The ion temperature of more than 10 keV has been achieved in relatively low density plasmas. When the strong ICRF heating is applied, it is observed that the high frequency and the low frequency fluctuations are excited and suppress the increase of the plasma parameters. Recently, a new high power gyrotron system has been constructed and the ECRH power in plug extends up to 370 kW. The improvement of the confinement due to the formation of the potential in the axial direction and the strong radial electric field shear has been observed.

EC wave plasma breakdown on GAMMA 10 device

“…The main plasma is magnetically confined in the central cell with auxiliary heatings of Ion Cyclotron Range of Frequency (ICRF), Electron Cyclotron Resonance Heating (ECRH) and Neutral Beam Injection (NBI) [1][2][3] coupled with the electric potential barrier confining configuration [1,4]. As the experimental setting for heating/building up the GAMMA 10 plasma, the experiments are operated in the high ion temperature mode [5] for aiming the higher plasma performance by sustaining the base plasma by ICRF and then secondarily heated by ECRH or NBI.…”